Catalysis over crystalline silicate ZSM-58

ABSTRACT

A process is provided for converting feedstock comprising hydrocarbon compounds to product comprising hydrocarbon compounds of lower molecular weight than feedstock hydrocarbon compounds over a catalyst comprising porous crystalline material having the structure of ZSM-58. In particular embodiments, the conversion is selective cracking for waxes and the process is useful for reducing the pour point of fuel oils and lubricants.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of application Ser. No. 861,789, filed May 9, 1986 now U.S. Pat. No. 4,698,217, which is a continuation-in-part of application Ser. No. 705,821, filed Feb. 26, 1985, now abandoned.

Application Ser. No. 861,790, filed May 9, 1986, now U.S. Pat. No. 4,665,264 is also a continuation-in-part of application Ser. No. 705,821, now abandoned.

Application Ser. No. 900,047, filed Aug. 25, 1986, is a continuation-in-part now allowed of application Ser. No. 749,240, filed June 27, 1985, now abandoned, which is also a continuation-in-part of application Ser. No. 705,821, now abandoned.

Application Ser. No. 905,996, filed Sept. 11, 1986 now allowed, is a continuation-in-part of application Ser. No. 749,242, filed June 27, 1985, now abandoned, which is also a continuation-in-part of application Ser. No. 705,821, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for conversion of feedstock comprising hydrocarbon compounds to conversion product comprising hydrocarbon compounds of lower molecular weight than feedstock hydrocarbon compounds, eg. cracking and dewaxing. The process comprises contacting, under conversion conditions, said feedstock with a catalyst comprising a synthetic, thermally stable, molecular shape selective, active form of crystaline material designated ZSM-58.

2. Description of the Prior Art

Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure as determined by X-ray diffraction, within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolitic material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as "molecular sieves" and are utilized in a variety of ways to take advantage of these properties.

Such molecular sieves, both natural and synthetic, include a wide variety of positive ion-containing crystalline aluminosilicates. These aluminosilicates can be described as a rigid three-dimensional framework of SiO₄ and AlO₄ in which the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen atoms is 1:2. The electrovalence of the tetrahedra containing aluminum is balanced by the inclusion in the crystal of a cation, for example an alkali metal or an alkaline earth metal cation. This can be expressed wherein the ratio of aluminum to the number of various cations, such as Ca/2, Sr/2, Na, K or Li, is equal to unity. One type of cation may be exchanged either entirely or partially with another type of cation utilizing ion exchange techniques in a conventional manner. By means of such cation exchange, it has been possible to vary the properties of a given aluminosilicate by suitable selection of the cation. The spaces between the tetrahedra are occupied by molecules of water prior to dehydration.

Prior art techniques have resulted in the formation of a great variety of synthetic zeolites. The zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No. 2,882,244), zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat. No. 3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752), zeolite ZSM-5 (U.S. Pat. No. 3,702,886), zeolite ZSM-11 (U.S. Pat. No. 3,709,979), zeolite ZSM-12 (U.S. Pat. No. 3,832,449), zeolite ZSM-20 (U.S. Pat. No. 3,972,983), ZSM-35 (U.S. Pat. No. 4,016,245), ZSM-38 (U.S. Pat. No. 4,046,859), and zeolite ZSM-23 (U.S. Pat. No. 4,076,842), merely to name a few.

The SiO₂ /Al₂ O₃ ratio of a given zeolite is often variable. For example, zeolite X can be synthesized with SiO₂ /Al₂ O₃ ratios of from 2 to 3; zeolite Y, from 3 to about 6. In some zeolites, the upper limit of the SiO₂ /Al₂ O₃ ratio is unbounded. ZSM-5 is one such example wherein the SiO₂ /Al₂ O₃ ratio is at least 5 and up to infinity. U.S. Pat. No. 3,941,871 (Re. 29,948) discloses a porous crystalline silicate made from a reaction mixture containing no deliberately added alumina in the recipe and exhibiting the X-ray diffraction pattern characteristic of ZSM-5. U.S. Pat. Nos. 4,061,724, 4,073,865 and 4,104,294 describe crystalline silicates or organosilicates of varying alumina and metal content.

SUMMARY OF THE INVENTION

The present invention is directed to a process for conversion of feedstock comprising hydrocarbon compounds to conversion product comprising hydrocarbon compounds of lower molecular weight than feedstock hydrocarbon compounds, eg. cracking and dewaxing. The process comprises contacting, under conversion conditions, said feedstock with a catalyst comprising a synthetic, thermally stable, molecular shape selective, active form of crystalline material designated ZSM-58.

The structure of ZSM-58 is distinguished from other crystalline silicates by a unique X-ray diffraction pattern. The typical X-ray diffraction pattern intensities for ZSM-58 are shown in Table 1, hereinafter.

The crystalline silicate ZSM-58 has a composition involving silica and alumina in the relationship

    (0.1-2)Al.sub.2 O.sub.3 :(100)SiO.sub.2.

In the as-synthesized form, ZSM-58 has a formula, on an anhydrous basis and in terms of moles of oxides per 100 moles of silica, as follows:

    (0.1-2.0)R.sub.2 O:(0.02-1.0)M.sub.2/n O:(0.1-2)Al.sub.2 O.sub.3 :(100)SiO.sub.2

wherein M is an alkali or alkaline earth metal cation, n is the valence of M, and R is an organic cation.

ZSM-58 is thermally stable and exhibits molecular shape selective properties as indicated by sorption tests.

EMBODIMENTS

The entire contents of application Ser. No. 861,789, filed May 9, 1986, are incorporated herein by reference.

The original alkali or alkaline earth metal cations of the as-synthesized ZSM-58 can be replaced in accordance with techniques well known in the art, at least in part, by ion exchange with other cations. Preferred replacing cations include metal ions, hydrogen ions, hydrogen precursor, e.g. ammonium, ions and mixtures thereof. Particularly preferred cations are those which render the ZSM-58 catalytically active, especially for certain hydrocarbon conversion reactions. These include hydrogen, rare earth metals and metals of Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic Table of the Elements.

Typical ion exchange technique would be to contact the synthetic ZSM-58 with a salt of the desired replacing cation or cations. Examples of such salts include the halides, e.g. chlorides, nitrates and sulfates.

ZSM-58 has a typical X-ray diffraction pattern which distinguishes it from other crystalline materials. The intensities of that pattern are as follows:

                  TABLE 1                                                          ______________________________________                                         Interplanar                                                                    d-Spacing (A) Relative Intensity, I/Io                                         ______________________________________                                         13.70 ± 0.20                                                                              W                                                                11.53 ± 0.20                                                                              .sup. W-VS                                                       10.38 ± 0.20                                                                              W                                                                7.82 ± 0.14                                                                               .sup. W-VS                                                       6.93-6.79 ± 0.14                                                                          .sup. W-VS                                                       6.19 ± 0.14                                                                               .sup. W-VS                                                       5.94 ± 0.12                                                                               W-M                                                              5.77 ± 0.12                                                                               VS                                                               5.22 ± 0.12                                                                               W                                                                5.18 ± 0.10                                                                               VS                                                               4.86 ± 0.09                                                                               M-S                                                              4.72 ± 0.08                                                                               S                                                                4.57 ± 0.08                                                                               W                                                                4.51 ± 0.08                                                                               S                                                                4.43 ± 0.08                                                                               W                                                                4.19 ± 0.08                                                                               W                                                                4.15 ± 0.08                                                                               M                                                                4.00 ± 0.07                                                                               W                                                                3.97 ± 0.07                                                                               W                                                                3.89 ± 0.07                                                                               W                                                                3.84 ± 0.07                                                                               M                                                                3.81 ± 0.07                                                                               W-M                                                              3.59 ± 0.06                                                                               W                                                                3.46 ± 0.06                                                                               W-M                                                              3.41 ± 0.06                                                                                 S-VS                                                           3.36 ± 0.06                                                                                 S-VS                                                           3.32 ± 0.06                                                                               M-S.sup.                                                         3.29 ± 0.05                                                                               W                                                                3.17 ± 0.05                                                                               W-M                                                              3.07 ± 0.05                                                                               W-M                                                              3.05 ± 0.05                                                                               W-M                                                              3.01 ± 0.05                                                                               W-M                                                              2.88 ± 0.05                                                                               W                                                                2.85 ± 0.05                                                                               W                                                                2.75 ± 0.05                                                                               W                                                                2.67 ± 0.04                                                                               W                                                                2.60 ± 0.04                                                                               W                                                                ______________________________________                                    

These values were determined by standard techniques. The radiation was the K-alpha doublet of copper and a diffractometer equipped with a scintillation counter and an associated computer was used. The peak heights, I, and the positions as a function of 2 theta, where theta is the Bragg angle, were determined using algorithms on the computer associated with the spectrometer. From these, the relative intensities, 100 I/I_(o), where I_(o) is the intensity of the strongest line or peak, and d (obs.) the interplanar spacing in Angstrom Units (A), corresponding to the recorded lines, were determined. In Table 1, the relative intensities are given in terms of the symbols W=weak, M=medium, S=strong and VS=very strong. In terms of intensities, these may be generally designated as follows:

W=0-20

M=20-40

S=40-60

VS=60-100

It should be understood that this X-ray diffraction pattern is characteristic of all the species of ZSM-58 compositions. The sodium form as well as other cationic forms reveal substantially the same pattern with some minor shifts in interplanar spacing and variation in relative intensity. Other minor variations can occur, depending on the silicon to aluminum ratio of the particular sample, as well as its degree of thermal treatment. Multiplets may be observed in the typical X-ray pattern for ZSM-58 at d-spacing values of 6.93-6.79±0.14, 4.86±0.09, 3.41±0.06, 3.07±0.05 and 3.01±0.05 Angstroms.

The crystalline silicate of the present invention can be used either in the alkali or alkaline earth metal form, e.g. the sodium or potassium form; the ammonium form; the hydrogen form or another univalent or multivalent cationic form. When used as a catalyst, ZSM-58 may be subjected to thermal treatment to remove part or all of any organic constituent.

The crystalline silicate can also be used as a catalyst in intimate combination with a hydrogenating component such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese, or a noble metal such as platinum or palladium where a hydrogenation-dehydrogenation function is to be performed. Such component can be exchanged into the composition to the extent aluminum is in the structure, impregnated therein or intimately physically admixed therewith. Such component can be impregnated in or on to it such as, for example in the case of platinum, by treating the ZSM-58 with a solution containing a platinum metal containing ion. Thus, suitable platinum compounds include chloroplatinic acid, platinous chloride and various compounds containing the platinum amine complex.

The above crystalline silicate, expecially in its metal, hydrogen and ammonium forms can be beneficially converted to another form by thermal treatment. This thermal treatment is generally performed by heating one of these forms at a temperature of at least 370° C. for at least 1 minute and generally not longer than 20 hours. While subatmospheric pressure can be employed for the thermal treatment, atmospheric pressure is desired for reasons of convenience. The thermal treatment can be performed at a temperature up to about 925° C. The thermally treated product is particularly useful in the catalysis of certain hydrocarbon conversion reactions.

The ZSM-58, when employed either as an adsorbent or as a catalyst in an organic compound conversion process should be dehydrated, at least partially. This can be done by heating to a temperature in the range of 200° C. to 595° in an inert atmosphere, such as air, nitrogen, etc. and at atmospheric, subatmospheric or superatmospheric pressures for between 30 minutes and 48 hours. Dehydration can also be performed at room temperature merely by placing ZSM-58 in a vacuum, but a longer time is required to obtain a sufficient amount of dehydration.

The ZSM-58 can be prepared from a reaction mixture containing sources of alkali or alkaline earth metal (M) cation, an oxide of aluminum, an oxide of silicon, an organic cation (R) of a methyltropinium salt, e.g. halide, hydroxide, sulfate, etc., and water, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:

    ______________________________________                                         Reactants      Useful    Preferred                                             ______________________________________                                         SiO.sub.2 /Al.sub.2 O.sub.3                                                                     50-1000 70-500                                                H.sub.2 O/SiO.sub.2                                                                             5-200   10-100                                                OH.sup.- /SiO.sub.2                                                                            0.-2.0   0.10-1.0                                              M/SiO.sub.2    0.01-3.0  0.10-1.0                                              R/SiO.sub.2    0.01-2.0  0.10-0.50                                             ______________________________________                                    

wherein R and M are as above defined.

Crystallization of the ZSM-58 can be carried out at either static or stirred condition in a suitable reactor vessel, such as for example, polypropylene jars or teflon lined or stainless steel autoclaves. The total useful range of temperatures for crystallization is from about 80° C. to about 225° C. for a time sufficient for crystallization to occur at the temperature used, e.g. from about 24 hours to about 60 days. Thereafter, the crystals are separated from the liquid and recovered. The reaction mixture can be prepared utilizing materials which supply the appropriate oxides. Such materials may include sodium silicate, silica hydrosol, silica gel, silicic acid, sodium hydroxide, a source of aluminum and the methyltropinium salt directing agent. The methyltropinium salt may be synthesized by selective methylation of 3-tropanol at the bridgehead nitrogen. This salt has the following formula: ##STR1## wherein x is an anion, such as, for example, a halide (e.g. iodide, chloride or bromide), nitrate, hydroxide, sulfate, bisulfate, perchlorate, etc.

It should be realized that the reaction mixture components can be supplied by more than one source. The reaction mixture can be prepared either batchwise or continuously. Crystal size and crystallization time of the new crystalline material will vary with the nature of the reaction mixture employed and the crystallization conditions.

In all cases, synthesis of the ZSM-58 crystals is facilitated by the presence of at least 0.01 percent, preferably 0.10 percent and still more preferably 1 percent, seed crystals (based on total weight) of crystalline product.

The crystals prepared by the instant invention can be shaped into a wide variety of particle sizes. Generally speaking, the particles can be in the form of a powder, a granule, or a molded product, such as an extrudate having particle size sufficient to pass through a 2 mesh (Tyler) screen and be retained on a 400 mesh (Tyler) screen. In cases where the catalyst is molded, such as by extrusion, the crystals can be extruded before drying or partially dried and then extruded.

The present invention provides a process for converting a feedstock comprising hydrocarbon compounds to conversion product comprising hydrocarbon compounds of lower molecular weight than feedstock hydrocarbon compounds which comprises contacting said feedstock at conversion conditions sufficient to convert said feestock to said product with a catalyst composition prepared by the method detailed herein.

In a specific embodiment, the present invention provides a process for catalytically dewaxing a heavy oil stock to provide a catalytically dewaxed oil with reduced wax content which comprises contacting said oil stock at catalytic dewaxing conditions in a reaction zone in the presence of hydrogen with a catalyst composition as herein defined.

In another specific embodiment, the present invention provides a process for catalytically hydrodewaxing a lubricating oil base stock to provide a catalytically hydrodewaxed lubricating oil base stock with reduced wax content which comprises contacting said stock at catalytic hydrodewaxing conditions in a reaction zone in the presence of hydrogen with a catalyst composition as herein defined.

In general, conversion conditions for the present process include a temperature of from about 100° C. to about 800° C., a pressure of from about 0.1 atmosphere (bar) to about 200 atmospheres, a weight hourly space velocity of from about 0.08 hr⁻¹ to about 2000 hr⁻¹ or a liquid hourly space velocity of from about 0.5 hr⁻¹ to about 100 hr³¹ 1, and a hydrogen/feedstock hydrocarbon compound mole ratio of from 0 (no added hydrogen) to about 100.

Such a conversion process includes, as a non-limiting example, cracking hydrocarbons to lower molecular weight hydrocarbons with reaction conditions preferably including a temperature of from about 230° C. to about 800° C., a pressure of from about 0.1 atmosphere (bar) to about 35 atmospheres, a weight hourly space velocity of from about 0.1 hr⁻¹ to about 200 hr⁻¹ or a liquid hourly space velocity of from about 0.6 hr⁻¹ to about 10 hr⁻¹, and a hydrogen/feedstock hydrocarbon compound mole ratio of from 0 to about 100.

When the feedstock to the present process comprises a heavy oil stock to be dewaxed, preferred conversion temperature is from about 230° C. to about 500° C. When the feedstock comprises a lubricating oil base stock to be dewaxed, preferred conversion temperature is also from about 230° C. to about 500° C., with a hydrogen/feedstock lubricating oil base stock mole ratio of from 0 to about 100.

As in the case of many catalysts, it is desired to incorporate the ZSM-58 with another material resistant to the temperatures and other conditions employed in the present process. Such materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and/or metal oxides such as alumina. The latter may be either naturally occurring or in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. Use of a material in conjunction with the ZSM-58 crystal, i.e. combined therewith, which is active, tends to change the conversion and/or selectivity of the catalyst. Inactive materials suitably serve as diluents to control the amount of conversion in a given process so that products can be obtained economically and orderly without employing other means for controlling the rate of reaction. These materials may be incorporated into naturally occurring clays, e.g. bentonite and kaolin, to improve the crush strength of the catalyst under commercial operating conditions. Said materials, i.e. clays, oxides, etc., function as binders for the catalyst. It is desirable to provide a catalyst having good crush strength because in commercial use it is desirable to prevent the catalyst from breaking down into powder-like materials. These clay binders have been employed normally only for the purpose of improving the crush strength of the catalyst.

Naturally occurring clays which can be composited with the ZSM-58 include the montmorillonite and kaolin family, which families include the subbentonites, and the kaolins commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite, or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification. Binders useful for compositing with the present crystal also include inorganic oxides, notably alumina.

In addition to the foregoing materials, the ZSM-58 crystal can be composited with a porous matrix material such as silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania as well as ternary compositions such as silica-alumina-thoria, silica-alumina-zirconia silica-alumina-magnesia and silica-magnesia-zirconia.

The relative proportions of finely divided crystalline material and inorganic oxide matrix vary widely, with the crystal content ranging from about 1 to about 90 percent by weight and more usually, particularly when the composite is prepared in the form of beads, in the range of about 2 to about 80 weight percent of the composite.

In order to more fully illustrate the nature of the invention and the manner of practicing same, the following examples are presented. In the examples whenever sorption data are set forth for comparison of sorptive capacities for cyclohexane and/or n-hexane, they were determined as follows:

A weighed sample of the calcined adsorbant was contacted with the desired pure adsorbate vapor in an adsorption chamber, evacuated to less than 1 mm and contacted with 80 mm Hg of n-hexane or cyclohexane vapor, pressures less than the vapor-liquid equilibrium pressure of the respective adsorbate at 90° C. The pressure was kept constant (within about ±0.5 mm) by addition of adsorbate vapor controlled by a manostat during the adsorption period, which did not exceed about 8 hours. As adsorbate was adsorbed by the new crystal, the decrease in pressure caused the manostat to open a valve which admitted more adsorbate vapor to the chamber to restore the above control pressures. Sorption was complete when the pressure change was not sufficient to activate the manostat. The increase in weight was calculated as the adsorption capacity of the sample in g/100 g of calcined adsorbant.

When Alpha Value is examined, it is noted that the Alpha Value is an approximate indication of the catalytic cracking activity of the catalyst compared to a standard catalyst and it gives the relative rate constant (rate of normal hexane conversion per volume of catalyst per unit time). It is based on the activity of the highly active silica-alumina cracking catalyst taken as an Alpha of 1 (Rate Constant=0.016 sec⁻¹). The Alpha Test is described in U.S. Pat. No. 3,354,078 and in The Journal of Catalysis, Vol. IV, pp. 522-529 (August 1965), each incorporated herein as to that description. It is noted that intrinsic rate constants for many acid-catalyzed reactions are proportional to the Alpha Value for a particular crystalline silicate catalyst, i.e. the rates for toluene disproportionation, xylene isomerization, alkene conversion and methanol conversion (see "The Active Site of Acidic Aluminosilicate Catalysts," Nature, Vol. 309, No. 5969, pp. 589-591, June 14, 1984).

EXAMPLES 1-6

Six separate synthesis reaction mixtures were prepared with compositions indicated in Table 2. The mixtures were prepared with silica sol (30 wt.% SiO₂), NaAlO₂, NaOH, a methyltropinium salt, i.e. iodide, and water. The mixtures were maintained at 160° C. for 4 days in a stainless steel, stirred (400 rpm) autoclave at autogenous pressure. Solids were separated from any unreacted components by filtration and then water washed, followed by drying at 110° C. The product crystals were analyzed by X-ray diffraction and chemical analysis. The product of Example 1 was found to be crystalline ZSM-58 with a trace of unidentified second component impurity. The products from Examples 2-6 proved to be 100 percent crystalline ZSM-58.

The X-ray diffraction pattern of the Example 4 crystals, after calcination at 538° C. for 17 hours in air, is set forth as illustration in Table 3. Other properties of each crystalline product are presented in Table 4. In the latter table, compositions are calculated on the basis of 100 (SiO₂ +AlO₂ ⁻) tetrahedra. The as-synthesized ZSM-58 from these examples contains from 3.8 to 5.0 methyltropinium cations (R) per 100 tetrahedra.

                  TABLE 2                                                          ______________________________________                                         Mixture Composition (mole ratios)                                                      SiO.sub.2 /                                                                              H.sub.2 O/                                                                             OH.sup.- /                                                                            Na+/  R*/                                     Experiment                                                                             Al.sub.2 O.sub.3                                                                         SiO.sub.2                                                                              SiO.sub.2                                                                             SiO.sub.2                                                                            SiO.sub.2                               ______________________________________                                         1       300       40      0.30   0.31  0.25                                    2       200       40      0.30   0.31  0.25                                    3       90        40      0.40   0.42  0.25                                    4       90        40      0.30   0.32  0.25                                    5       90        40      0.30   0.32  0.25                                    6       70        40      0.30   0.33  0.25                                    ______________________________________                                          *R = methyltropinium cation                                              

                  TABLE 3                                                          ______________________________________                                                        Observed Relative                                               d (A)          2 Theta  Intensity                                              ______________________________________                                         13.57425        6.511   7.4                                                    11.44933        7.721   51.2                                                   10.29541        8.588   4.1                                                    7.76959        11.389   53.6                                                   6.89736        12.834   60.1                                                   6.84556        12.932   33.0                                                   6.15999        14.378   57.8                                                   5.91115        14.987   19.5                                                   5.74071        15.435   85.8                                                   5.16339        17.173   100.0                                                  4.84326        18.317   51.9                                                   4.70389        18.865   56.0                                                   4.52632        19.612   20.3                                                   4.49392        19.755   51.7                                                   4.41905        20.093   4.7                                                    4.13559        21.486   26.0                                                   3.98517        22.307   11.8                                                   3.96826        22.404   8.9                                                    3.87191        22.969   17.1                                                   3.82281        23.268   30.6                                                   3.80712        23.365   25.6                                                   3.57841        24.882   16.2                                                   3.44668        25.849   35.2                                                   3.38811        26.303   96.5                                                   3.35769        26.546   86.7                                                   3.34862        26.619   80.8                                                   3.30859        26.947   66.2                                                   3.28346        27.158   9.1                                                    3.16039        28.237   23.3                                                   3.06246        29.159   26.8                                                   3.06070        29.176   31.2                                                   3.03737        29.406   22.7                                                   2.99654        29.816   25.2                                                   2.98814        29.901   21.2                                                   2.87045        31.158   4.1                                                    2.84237        31.473   5.1                                                    2.66429        33.638   5.5                                                    2.58922        34.643   4.8                                                    2.50349        35.869   4.3                                                    2.48809        36.099   6.3                                                    2.43821        36.863   9.0                                                    2.42105        37.134   14.9                                                   2.39052        37.626   5.8                                                    2.35412        38.230   2.8                                                    2.33296        38.591   4.3                                                    2.30029        39.161   16.7                                                   2.23686        40.319   2.4                                                    2.23188        40.413   1.9                                                    2.21126        40.807   3.2                                                    2.16400        41.739   1.7                                                    2.11106        42.836   1.4                                                    2.07314        43.660   3.0                                                    2.03910        44.427   0.3                                                    1.97783        45.880   11.4                                                   1.95022        46.568   4.4                                                    1.93214        47.030   3.9                                                    1.91503        47.476   3.7                                                    1.83810        49.594   6.4                                                    1.83554        49.667   5.5                                                    ______________________________________                                    

                                      TABLE 4                                      __________________________________________________________________________     Moles C    Moles per Mole Al.sub.2 O.sub.3                                                            COMPOSITION                                             Experiment                                                                           Mole N                                                                              N.sub.2 O                                                                          Na.sub.2 O                                                                         SiO.sub.2                                                                          Al/100 T.sub.d                                                                       Na+/100 T.sub.d                                                                       N+/100 T.sub.d                                                                       R/100 T.sub.d                        __________________________________________________________________________     1      9.5 4.09                                                                               0.85                                                                               223  0.89 0.76   3.6   3.8                                  2     11.2 2.43                                                                               0.74                                                                               140 1.4   1.0    3.4   4.2                                  3      9.6 1.85                                                                               0.13                                                                               83  2.4   0.30   4.4   4.7                                  4     10.2 1.69                                                                               0.12                                                                               78  2.5   0.30   4.2   4.8                                  5     10.8 1.77                                                                               0.25                                                                               85  2.3   0.58   4.1   4.9                                  6      9.6 1.50                                                                               0.10                                                                               62  3.1   0.30   4.7   5.0                                  __________________________________________________________________________

EXAMPLE 7

A sample of the Example 4 product crystals, having been calcined in nitrogen for 4 hours at 500° C., ammonium exchanged and then converted to the hydrogen form, was subjected to the sorption test. Significant n-hexane, i.e. 8 weight percent at 90° C., was sorbed while only minimal cyclohexane (about 1 weight percent at 90° C.) sorbed at 80 torr hexane partial pressure. This indicates molecular shape selectivity for ZSM-58.

EXAMPLE 8

The sample of Example 4 product used for sorption evaluation was evaluated in the Alpha Test. Its Alpha Value proved to be 13 at 538° C. Thus, ZSM-58 is about thirteen times more active than highly active silica-alumina in the Alpha Test. 

What is claimed is:
 1. A process for catalytically reducing the wax content of a wax-containing feedstock, which process comprises contacting said feedstock at conversion conditions including a temperature of from about 100° C. to about 800° C., a pressure of from about 0.1 atmosphere to about 200 atmospheres, a weight hourly space velocity of from about 0.08 hr⁻¹ to about 2000 hr⁻¹ and a hydrogen/feedstock hydrocarbon mole ratio of from 0 to about 100 with a catalyst composition comprising ZSM-58.
 2. The process of claim 1 wherein said ZSM-58 has been treated to replace original cations, at least in part, with a cation or mixture of cations selected from the group consisting of hydrogen, hydrogen precursors, rare earth metals, and metals of Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic Table.
 3. The process of claim 2 wherein said replacing cations are hydrogen or hydrogen precursor.
 4. The process of claim 1 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 5. The process of claim 2 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 6. The process of claim 4 wherein said matrix is alumina-containing material.
 7. The process of claim 5 wherein said matrix is alumina-containing material.
 8. The process of claim 4 wherein said catalyst composition is in the form of an extrudate.
 9. The process of claim 4 wherein said catalyst composition is in the form of beads.
 10. The process of claim 1 wherein said conversion conditions include a temperature of from about 230° C. to about 800° C., a pressure of from about 0.1 atmosphere to about 35 atmospheres and a weight hourly space velocity of from about 0.1 hr⁻¹ to about 200 hr⁻¹.
 11. A process for catalytically dewaxing a hydrocarbon oil feed to provide a catalytically dewaxed oil with reduced pour point, which process comprises contacting said feed at a temperature of from about 230° C. to about 500° C., a pressure of from about 0.1 atmosphere to about 200 atmospheres and a weight hourly space velocity of from about 0.08 hr⁻¹ to about 2000 hr⁻¹ with a catalyst composition comprising ZSM-58.
 12. The process of claim 11 wherein said ZSM-58 has been treated to replace original cations, at least in part, with a cation or mixture of cations selected from the group consisting of hydrogen, hydrogen precursors, rear earth metals, and metals of Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic Table.
 13. The process of claim 12 wherein said replacing cations are hydrogen or hydrogen precursor.
 14. The process of claim 11 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 15. The process of claim 12 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 16. The process of claim 14 wherein said matrix is alumina-containing material.
 17. The process of claim 15 wherein said matrix is alumina-containing material.
 18. The process of claim 14 wherein said catalyst composition is in the form of an extrudate.
 19. The process of claim 14 wherein said catalyst composition is in the form of beads.
 20. A process for catalytically dewaxing a lubricating oil base stock to provide a lubricating oil with reduced pour point, which process comprises contacting said base stock at a temperature of from about 230° C. to about 500° C., a pressure of from about 0.1 atmosphere to about 200 atmospheres, a weight hourly space velocity of from about 0.08 hr⁻¹ to about 2000 hr⁻¹ and a hydrogen/oil mole ratio of from 0 to about 100 with a catalyst composition comprising ZSM-58.
 21. The process of claim 20 wherein said ZSM-58 has been treated to replace original cations, at least in part, with a cation or mixture of cations selected from the group consisting of hydrogen, hydrogen precursors, rare earth metals, and metals of Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic Table.
 22. The process of claim 21 wherein said replacing cations are hydrogen or hydrogen precursor.
 23. The process of claim 20 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 24. The process of claim 21 wherein said catalyst composition comprises said ZSM-58 and a matrix.
 25. The process of claim 23 wherein said matrix is alumina-containing material.
 26. The process of claim 24 wherein said matrix is alumina-containing material.
 27. The process of claim 23 wherein said catalyst composition is in the form of an extrudate.
 28. The process of claim 23 wherein said catalyst composition is in the form of beads. 